The AvMaster Relay is the first and only self contained, fail-safe, avionics master relay package to protect expensive radio gear at an affordable price. The AvMaster Relay is installed between the power bus and the protected radios. The avionics master switch then controls the AvMaster Relay only and not the radios directly. Not only does the AvMaster Relay protect the system from transient electrical spikes during normal operations, its four parallel relay controlled circuits allow for individual fusing that separate all radios from each other. The fail-safe design of AvMaster Relay eliminates the need for a backup avionics master switch. If the avionics master switch ever fails, the pilot won't even realize it after the flight is over and the avionics master doesn't shut down the radio stack. The radios will just be controlled individually until the problem is resolved.

One setup in the cockpit that can help master the forces of physical and electronic problems for avionics is the avionics master. The function of the avionics master is simple enough: It allows a central point to provide power to the electronics in your cockpit. The avionics master accomplishes this protective mission through either the use of a switched breaker or a relay system, either of which allow the pilot to connect or disconnect the avionics from the electrical system in a single, simple manner.

This ability is important for a number of reasons. First off, your airplane contains many devices that can put some strain on your avionics in the form of an inductive kick. An inductive kick is a voltage spike that generally occurs when the electric motors in the airplanes stop. A motor is an inductor, and when the power is cut off, either through a switch or by reaching a travel point in the case of a flap or landing-gear motor, the device releases its magnetic field in the form of a voltage spike. The size of the spike is proportional to the size of the motor, but in aircraft, these transient electrical spikes can reach several times the normal rated load and can damage delicate avionics. While avionics are hardened against these electrical assaults, each one takes a toll on the avionics if they are left on when the spike occur. Where this will typically turn up is in reduced service life before repairs are needed.

What is the max current load that this unit can handle?
Per the manual for the 28V relay, the maximum current per relay is 25A. Maximum Voltage is 32V.
Is this TSO'd, for certified planes?
Per the supplier: No, this does not have FAA TSO approval.